The majority of the Philips LED portfolio is dimmable. This means that you can adjust the light intensity. Dimmability is always clearly indicated on the commercial packaging, in the user manual and on the website. Philips LED luminaires can be dimmed with phase cutting dimmers (not included in the packaging), both wall and home automation systems (DIN rail).
Below is a list of Philips tested wall dimmers which are compatible with Philips LED luminaires:

www.philips.com/dimmableled

These dimmers are tested in a laboratory environment, in various scenarios to ensure a wide array of possible home experiences. However, in case of doubts, please consult a lighting professional to ensure all safety requirements and standards are met for your personal situation.
Following external factors can influence the dimming behavior :

• Other loads than the Philips luminaire in the same electrical circuit
• Total wattage load too high in relation to allowed dimmer load
• Max. 8 drivers (10 or 30W) on 1 dimmer

Please check the user manual of the dimmer (eg. adjustment need for the screw or the dimmer might not be set in right position, etc)
Some other articles are equipped with integrated dimmers (indication on commercial packaging, user manual & website).